Buggy code:
@ JsonIgnoreProperties ( ignoreUnknown = true ) public class ModelConfig { private ModelBasicConf basic = new ModelBasicConf ( ) ; private ModelSourceDataConf dataSet = new ModelSourceDataConf ( ) ; private ModelStatsConf stats = new ModelStatsConf ( ) ; private ModelVarSelectConf varSelect = new ModelVarSelectConf ( ) ; private ModelNormalizeConf normalize = new ModelNormalizeConf ( ) ; private ModelTrainConf train = new ModelTrainConf ( ) ; private List < EvalConfig > evals = new ArrayList < EvalConfig > ( ) ; public ModelBasicConf getBasic ( ) { } public void setBasic ( ModelBasicConf basic ) { } public ModelSourceDataConf getDataSet ( ) { } public void setDataSet ( ModelSourceDataConf dataSet ) { } public ModelStatsConf getStats ( ) { } public void setStats ( ModelStatsConf stats ) { } public ModelVarSelectConf getVarSelect ( ) { } public void setVarSelect ( ModelVarSelectConf varSelect ) { } public ModelNormalizeConf getNormalize ( ) { } public void setNormalize ( ModelNormalizeConf normalize ) { } public ModelTrainConf getTrain ( ) { } public void setTrain ( ModelTrainConf train ) { } public List < EvalConfig > getEvals ( ) { } public void setEvals ( List < EvalConfig > evals ) { } public static ModelConfig createInitModelConfig ( String modelName , ALGORITHM alg , String description ) throws IOException { } @ JsonIgnore public boolean isLocalFileSystem ( ) { } @ JsonIgnore public boolean isHdfsFileSystem ( ) { } @ JsonIgnore public String getDataSetDelimiter ( ) { } @ JsonIgnore public int getBaggingNum ( ) { } @ JsonIgnore public Double getNormalizeStdDevCutOff ( ) { } @ JsonIgnore public MissValueFillType getNormalizeMissValueFillType ( ) { <START_BUG> return normalize . getFillType ( ) ; <END_BUG> } @ JsonIgnore public boolean isBinningSampleNegOnly ( ) { } @ JsonIgnore public Double getBinningSampleRate ( ) { } @ JsonIgnore public List < String > getPosTags ( ) { } @ JsonIgnore public List < String > getPosTags ( EvalConfig evalConfig ) { } @ JsonIgnore public List < String > getNegTags ( ) { } @ JsonIgnore public List < String > getNegTags ( EvalConfig evalConfig ) { } @ JsonIgnore public Double getNormalizeSampleRate ( ) { } @ JsonIgnore public Boolean isNormalizeSampleNegOnly ( ) { } @ JsonIgnore public int getBinningExpectedNum ( ) { } @ JsonIgnore public BinningMethod getBinningMethod ( ) { } @ JsonIgnore public boolean isTrainOnDisk ( ) { } @ JsonIgnore public Double getCrossValidationRate ( ) { } @ JsonIgnore public Double getBaggingSampleRate ( ) { } @ JsonIgnore public boolean isFixInitialInput ( ) { } @ JsonIgnore public boolean isBaggingWithReplacement ( ) { } @ JsonIgnore public String getAlgorithm ( ) { } @ JsonIgnore public String getModelSetName ( ) { } @ JsonIgnore public Integer getAutoTypeThreshold ( ) { } @ JsonIgnore public Double getNumericalValueThreshold ( ) { } @ JsonIgnore public void setModelSetName ( String modelSetName ) { } @ JsonIgnore public void setModelSetCreator ( String author ) { } @ JsonIgnore public String getDataSetRawPath ( ) { } @ JsonIgnore public boolean isVariableStoreEnabled ( ) { } @ JsonIgnore public String getTargetColumnName ( ) { } @ JsonIgnore public String getTargetColumnName ( EvalConfig evalConfig ) { } @ JsonIgnore public boolean isMapReduceRunMode ( ) { } @ JsonIgnore public boolean isLocalRunMode ( ) { } @ JsonIgnore public Boolean getVarSelectWrapperEnabled ( ) { } @ JsonIgnore public List < String > getMetaColumnNames ( ) throws IOException { } @ JsonIgnore public List < String > getCategoricalColumnNames ( ) throws IOException { } @ JsonIgnore public Map < String , Object > getParams ( ) { } @ JsonIgnore public void setParams ( Map < String , Object > params ) { } @ JsonIgnore public String getFilterExpressions ( ) { } @ JsonIgnore public Boolean getVarSelectFilterEnabled ( ) { } @ JsonIgnore public Integer getVarSelectFilterNum ( ) { } @ JsonIgnore public String getVarSelectFilterBy ( ) { } @ JsonIgnore public boolean isCategoricalDisabled ( ) { } @ JsonIgnore public String getVarSelectWrapperBy ( ) { } @ JsonIgnore public int getVarSelectWrapperNum ( ) { } @ JsonIgnore public int getNumTrainEpochs ( ) { } @ JsonIgnore public String getMode ( ) { } @ JsonIgnore public List < String > getListForceRemove ( ) throws IOException { } @ JsonIgnore public List < String > getListForceSelect ( ) throws IOException { } @ JsonIgnore public String getModelSetPath ( ) { } @ JsonIgnore public Boolean isBinningAutoTypeEnabled ( ) { } @ JsonIgnore public Integer getBinningAutoTypeThreshold ( ) { } @ JsonIgnore public Boolean isBinningMergeEnabled ( ) { } @ JsonIgnore public String getWeightColumnName ( ) { } @ JsonIgnore public String getHeaderPath ( ) { } @ JsonIgnore public String getHeaderDelimiter ( ) { } @ JsonIgnore public BinningAlgorithm getBinningAlgorithm ( ) { } @ JsonIgnore public void setBinningAlgorithm ( BinningAlgorithm binningAlgorithm ) { } @ JsonIgnore public EvalConfig getEvalConfigByName ( String evalSetName ) { } @ Override public boolean equals ( Object obj ) { } }

Fix:
return normalize . getMissValueFillType ( ) ;